What Are Painkillers, Know Their Types, Side Effects & Who Should Avoid Painkillers

What are Painkillers?

Painkillers are medications that are commonly used to ease or treat pain. There is a huge variety of painkillers available in the market, and they all come in various forms and types. Some pain killers medications are prescribed while others are easily available over-the-counter. They can be taken orally, injected, applied, or through the rectum as suppositories. There is an extensive list of painkillers available, but there are only four main types that are commonly used, and they each work in different ways. Pain relief medications, also known as painkillers and analgesics, are the most widely used solution for pain relief. And over a thousand billion painkillers are taken annually, throughout the world, this is because over-the-counter painkillers are the quickest way to relieve pain, however, recent news and studies have shown how some of the widely used generic painkillers can have adverse effects and several side effects, which asks for serious consideration.

Recently, the Food and Drug administration have shown concern over some commonly used painkillers, such as paracetamol and ibuprofen, stating that these medications can cause high blood pressure. Other studies have shown painkillers can increase the risk of heart attack, chances of stroke, high cholesterol and kidney diseases. In spite of all these revelations, painkillers are still being consumed widely and daily as they offer quick pain relief.

What are Painkillers?

The Food and Drug Administration in 2012 stated that certain product labels that have acetaminophen (which is an active ingredient found in Tylenol), carry warnings stating that the particular drug can cause liver damage if taken in high dosage or if the recommended dosage is exceeded. This has lead to more rigorous researches as over the years death rate from over dosage, unsupervised and illicit use of particular painkillers have increased along with an increased emergency visit to hospitals. Most of the death from overdose has been attributed to painkillers, which is a major cause of concern. In spite of such warnings and reports, painkillers are still consumed. The consumption of painkillers have not reduced because of the simple reason, that painkillers are thought to be necessary, as they provide quick relief and are easily available. Since the consumption of painkillers cannot be stopped completely, there are a few cautionary steps that one could take to reduce the chances of risks attached with taking painkillers.

It is first necessary to know the different types of painkillers that are available and have a better understanding of what they do.

Types of Painkillers & Their Side Effects

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

As the name suggests, NSAIDS are the type of painkillers that are non-steroidal and anti-inflammatory, and most over-the-counter painkillers are of this kind. They are most commonly used pain killers that help relieve minor pains and aches and fever. NSAIDs block the effects of enzymes like cyclooxygenase enzymes, which help in the production of other chemicals called prostaglandins. Prostaglandins are responsible in causing pain and inflammation in areas that are either damaged or injured. NSAIDs help in reducing the production of prostaglandin which helps with the reduction of pain and inflammation. NSAIDs include aspirin, ibuprofen, diclofenac, naproxen and other medications used for allergies, sinus pressure and colds. NSAIDs are usually prescribed for mild pain, for instance, pain in muscles, or back, joints, which are linked to arthritis, or mild to moderate pain like headaches and osteoarthritis. It is also prescribed in case of inflammation. It is important to note that not all the available NSAIDs work in the same manner and therefore should not be taken with the hope of reducing pain. Some NSAIDs work differently than others. NSAIDs are considered one of the safe and effective type of painkillers. However, NSAIDs are found to cause stomach problems, such as cardiovascular disease and ulcers. If you are taking ibuprofen or diclofenac, it should be taken with or after food, as it can irritate the lining of the stomach and cause bleeding in the gut and stomach.

Some Possible Side-Effects of NSAIDs: When taken in recommended doses, NSAIDs have minimal to no side effects. NSAIDs when taken in short courses and only once in a while when the pain becomes intolerable, does not usually cause any serious or severe side-effects. However, in some cases it is found that the possible side-effects of NSAIDs are bleeding in the gut and stomach, and cardiovascular issues. NSAIDs must be avoided or one should ask for your doctor’s recommendation before taking the medicines, if you have had heart attacks, or stroke, or if you use aspirin for heart protection. You must also avoid NSAIDs if you have high blood pressure or kidney disease.

Acetaminophen/ Paracetamol

Also known as paracetamol, acetaminophen is the second type of pain killer that is available over-the-counter. Acetaminophen or paracetamol is one of the safest and effective painkillers used all over the world. Acetaminophen is an active ingredient that is found in several over-the-counter medications, they are also often prescribed.

Acetaminophen or paracetamol is an effective painkiller that is also considered to be safe even during pregnancy. They are gentler on the stomach, which makes them a safe option. Paracetamol helps in reducing temperature which relieves pain. They reduce the symptoms of flu, which is why they are often used for minor colds and fever as well. Some common acetaminophens include: cough suppressants, cold medications and pain relievers. Paracetamol is mostly prescribed when pain is not severe and there is no inflammation. Even though acetaminophen is a painkiller, which is effective and safe to use and are often used for children as well, but they have been found to be harmful for people who have a history of liver problems, who are heavy drinkers, and asthmatics, who take paracetamol more regularly, which increases the chance of frequent and severe attacks. Recommended dosage of paracetamol for adults is 500 mg-1g, with an interval of four to six hours. The maximum dosage is 4 g, but this is for severe cases only.

Some Possible Side-effects of Acetaminophen/Paracetamol: There are no serious side-effects to using paracetamol, when taken in recommended doses and only when it is required. However, paracetamol has adverse and severe effects in case of an overdose where it can permanently damage the liver and can also cause death. Most cases of paracetamol overdose have occurred by accident; therefore extreme precaution is always advised.


These painkillers can be in 2 forms, weak opioids and strong opioids. Each is used and prescribed for different needs. Opioids bind to certain opioid receptors in the gut, central nervous system, and other parts of the body. This binding leads to reduced feeling of pain, and the tolerance to pain increases as the pain felt is marginally reduced.

Some commonly used opioids are dihydrocodeine and codeine, which are weak opioids. Some strong opioids include pethidine, morphine, tramadol and oxycodone. Strong opioids are only prescribed in extreme cases of severe pain, where some of the people in need of strong opioids are often admitted to hospital. Weak opioids are generally prescribed for pain, when other drugs like paracetamol or NSAIDs, such as ibuprofen, have not had any effect in relieving. Strong opioids are prescribed to relieve severe pain, such as pain after surgery or operation, during cancer, and severe injuries from an accident or other reasons.

Some Possible Side-effects of Opioids. Opioids are comparatively stronger painkillers than NSAIDs or paracetamol. Opioids need to be prescribed, but could also be available for self-treatment. Some of the common side-effects associated with opioids are dry mouth, constipation, nausea, vomiting, confusion and drowsiness.

Topical Anti-inflammatory Painkillers

Other medicines used for pain relief are anti-inflammatory medicines, which come in the form of cream or ointment; they are also known as topical painkillers and are generally and usually used on muscles or soft tissues. Anti-inflammatory painkillers are often used to ease muscle pulls, muscle pain, strains, and sprains. They could also be used for painful arthritis as a temporary relief. Anti-inflammatory painkillers are often prescribed over oral anti-inflammatory medications, as these topical pain killers are safer and have minimum side effects. Topical anti-inflammatory painkillers also come in the form of capsules, tablets or liquids, which can be taken orally, injected, or applied. They are available as gel patches, gels, foams and sprays. These topical painkillers contain medicines such as felbinac, ketoprofen, ibuprofen, diclofenac and piroxicam that are anti-inflammatory in nature. Topical anti-inflammatory painkillers work in similar manner as NSAIDs, but instead of blocking the effect of prostaglandins and having an effect on the entire body; it only affects the areas where it is applied. The topical painkiller gets absorbed into the skin once applied and seeps deeper into the skin into the area of pain or inflammation. Topical painkillers reduce risks of side-effects as the amount of anti-inflammatory is far less in the body, than taking NSAIDs, and it is only applied to a particular area. All this makes topical painkiller one of the safest pain killers. However, the effect of topical painkiller does not last as long as taking oral painkillers, as the amount is far less and it does not affect the entire body. Topical painkillers can only be effective for acute pain, and they are not generally prescribed or used for chronic pain conditions. It is important to know that some topical painkillers can cause sensitivity to light (this is called photosensitivity) for a duration of time, especially if you are using an ointment that contains ketoprofen, in which case, you must cover the areas where the ketoprofen ointment has been applied, or avoid going into light, if possible.

Also, avoid exposing your skin to sunlight for the duration of the treatment, and two weeks after having completed the treatment. Some people have reported of allergic reactions and skin burns, which is why getting checked for allergies or asking for your doctor’s recommendation is advised. It is also important to know the amount to apply and how to apply the painkiller effectively, and always avoid applying painkiller on broken skin near the mouth, eyes, nose, or genitals and anal areas. It is also important to remember to clean your hands before and after applying the topical painkiller, and avoid getting it into sensitive areas, such as the eyes.

Who Should Avoid Painkillers?

If you have had any serious allergic reaction to any particular kind or type of painkiller in the past, then it is best to find an alternative before taking any type of painkiller. Drugs like aspirin cannot be given to children under the age of 16, as it might result in the child developing Reye’s syndrome, which is a rare condition, but there is a probability of the child developing the condition. People with heart problem or kidney issues should avoid painkillers, and only take prescribed medications, as most painkillers are found to cause heart attacks or kidney problem; therefore it is best to avoid these medications under such circumstances.


So, these were the most common types of safe and effective painkillers that are either prescribed or used as self-treatment. However, each of the type of drug carries a various number of side effects or even serious adverse effects, which is why painkillers should be taken with caution, and the recommended dosage should not be exceeded under any circumstances. Painkillers have the capability to interfere and interact with other medications that are taken, which could result in reduced effectiveness of the other medication or the painkiller itself. It could also result in reactions. Painkillers are only for temporary relief, and should be used as a relief for the shortest period of time possible, and within the recommended dose. Painkillers are mostly taken for few days, in case of minor pain like muscle pull, toothache or headache. However, there are cases where one might need to take painkillers for a longer duration of time due to some chronic conditions like chronic back pain, osteoarthritis or rheumatoid arthritis.

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Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:November 2, 2021

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